Recently widely available photovoltaic power generation systems include a system-association type, which supplies a commercial-use power system with AC power obtained by an inverter performing DC/AC conversion of power generated by a solar battery, and an independent type which supplies power to a load.
An AC module, integrally comprising a solar battery and an inverter circuit, for outputting AC power has recently come to practical use. As one of the configurations of the AC module, Japanese Patent Application Laid-Open No. 10-14111 proposes an AC module which enables an increase in the number of parallel-connected AC modules by sequentially repeating cascade connection.
The AC module disclosed in Japanese Patent Application Laid-Open No. 10-14111 enables easy parallel connection of plural AC modules by way of cascade connection. On the other hand, an improvident increase of the number of connections causes the current in a connector or current path of the AC module to exceed the rated current. Furthermore, if the rated current of a connector or current path of the AC module is increased on the assumption that the insolation becomes extremely intense, the cost of the AC module will increase.